Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/82

 M O R

M O R

the tbys of JufKniai*. that they knew it was Spun by worms. Their ignorance of the origin of filk, however, no more al- tered its nature, than their ignorance of the fabric of their morrhina vaja did that of the fubftance they were made of.

The antients had their moft elegant and valuable 7norrhina i vaja from India and Carmania ; but Arrian tells us, that there was a great quantity of them made at Diofpolis in YEgypt. This he calls another fort of Morrhina work ; and it is evi- dent, -from all accounts, that the morrha of Diofpolis was a fort of glafs ware, made in imitation of the porcelane or morrha of India.

There is fome difference in the accounts given by Pliny and Martial, of the Morrhina vaja. The firft author fays, that they would not bear hot liquors, but that only cold ones were drank out of them. The latter, on the other hand, tells us, that they bore hot liquors very well. It mould feem, that the moft credit was to be given to Pliny; but iffo, their porce- lane was greatly inferior to ours in this particular.

MORSE; in zoology, the name of a monttrous fea animal, called by fome the rofmarus and walrus, and by others, very improperly, the hippopotamus and eauus marinus, bee the ar- ticle Hippopotamus.

The Morfe is an ill-fliapcd amphibious animal, of the Size of a large ox, covered with a Skin like that of the feal, and fomewhat refembling an ox in the head; for which reafon fome have called it the fea cow, or vacca marina, whence it has been erroncoufly confounded by fome with the manati. It has two large prominent and crooked teeth before, which are as fine as ivory, and are ufed by artificers for the fame purpo- fes. It brings forth ufually but one young one at a time, ne- ver more than two. It is a very firong and vigorous animal, and difficultly taken ; when it is caught, it is ufually at land, Seldom at fea. ' Vorftius, who met with a young one of this creature, has very accurately defcribed it ; whence we have the beft de- fcription extant of the nature of the animal. This young one was of the fize of a large dog, and in fhape much rckinbled the phoca or fea calf. Its head was round ; its eyes large, and like thofe of an ox; its noiTrils deprefled and wide, and opening, and drawing together as the creature pleafed. It had apertures on the tides of rhe head for ears. 1 Its mouth opened round and not very large ; and on the upper lip it had a fort of whifkers, compofed of thick cartilaginous briftles. The lower jaw was of a trigonal form ; the tongue fhort and thick, and the mouth well furnifh'd with broad and flatted teeth. Its fore fact, as well as the hinder ones, were very broad ; and the hinder extremity of its body very much re- fembled that of the phoca or fea calf. When it walked, the fore feet were directed forwards, the others turned backward. The toes were five on each foot, and thefe were joined by a membrane, which was remarkably thick. The hinder feet had claws, the fore ones had not ; and the creature had no tail, and crept rather than walked on the hinder parts. Its fkin was thick and tough, and covered with a few fhort grey hairs. It made a noife like the grunting of a hog. Ray's Syn. Quad. p. iqi.

MORT {Cyd.) — Mort, among the fifhermen of fome parts of England, a name given to the falmon while in its third year's growth. JVillughifs Hift. Pifc. p. 189. Sec the article Salmon.

MORTALITY {Cyd.)— Bills of Mortality. Mr.Simpfon makes the proportion of the number of inhabitants of any place, to the number of births that happen there annually, as 26 to j. Whereas Mr. Kerfleboom a makes it 35 to 1 ; which Mr. Simpfon thinks owing to a want of obfervations. But Mr. Kerfloboom has Since fhewn, in 29 tables, that the proportion of 26 to I cannot be admitted, and that his own. of 35 to 1, is right. He alfo proves, from Mr. Maitland's obfervations, that children in London, of two years old, con- tinue to live, on a medium, above 37 years; and he ob- serves, that by Dr. Halley's table b, they live 3^. — [ a Doetr. ofAnnuit. p. 127. * Phil. Tranf. N'. 465. Sect. 3. P-3IQ-]

Mr. Kerffeboom fuppofes, that out of every ico children born, five come dead into the world ; and chat out of every 300 children born alive, near 20 die under a year old. Mr. Simpfon's calculation differs greatly from this, he fuppofing that full 32 out of 100 children, die under a year old. Phil. Tranf. ibid.

There is a furprizing difparity obferved between the chriften- ings and burials of the city of London ; which is chiefly owing to diflenters of all forts baptizing their children without fend- ing in accounts of their chriftenings to the parifh clerk. See Mr. Ma'uland in Phil. Tranf. N°. 450. Sect. 16. From the account there given of the chriftenings and burials in London for ten years, from 1626 to 1635 jnclufive, it ap- . pears that the chriftenings exceeded the burials ; nor can it be doubted that they do fu ftill. This obfervation will fhew the caufe of fome mistakes of Mr. Kerffeboom. See Phil. Tranf. ibid.

Mr.Maitland, in his account of London, fhews, that at a medium of nine years, there are annually buried in London 59542, and in Paris only 17804; (o that the number of in-

habitants in London exceed thofe in Paris by nearly in the pro- portion of 5 to 3. Hilt, of Lond. p. 540, 548. MORTAR (Cyd.) — The falt-petre workers in trance ufing the Mortar of old buildings for extracting that fait, Mr. Petit has thought it worthy a peculiar attention, and has made Several trials, by way of anafylis, of Mortar, to determine whether it really and eflentially contains nitre in it, or whether it be only Serviceable in that mixture of Salts from which nitre is produced.

The common managers of the faltpetre -works are of opinion, that Mortar contains in it all the faltpetre they procure from it, -and that the wood-afhes, and other fubitances they ufe with it, only ferve to abforb the fat or oily parts, and fo fet ■ the faltpetre at liberty to fhoot. This they pretend to affirm upon experience ; but they do not coniider that tho' they can procure faltpetre from the rubbifh or Mortar without the ad- dition of wood-allies, yet it is not pure Mortar that they make their experiments upon, but fuch as is taken from their own heaps, upon which they always throw all the refiduum of their former works, and all that liquor which will fhoot no more cryftals, but which they call the mother- water of Salt- petre.

This gentleman therefore very properly judged, that to make a regular trial of the Mortar or rubbifh alone, he muft not take it from their ftores, ufed in the faltpetre- works, but pick ithimfelf from the ruins of old buildings. The mark the falt-petre workers have to know good Mortar for their purpofe, is, that it taftes acrid and fait when applied to the tongue ; but to this it may be alfo added, that it ought to be of a greyifh colour, and fuch as when powdered and Sprinkled upon burning charcoal yields fome fparks of fire; and the more fparks it gives, the better it is for the purpofe. And another character of the goodnefs is, that thefe well im- pregnated Mortars have a certain unctuofity or fattinefs to the touch, which other kinds have nvi.

The fineit of all kinds of Mortar for falt-petre work, is fuch as is had from the ruins of old buildings in a low Situation, and out oS the way of much funfhine ; where there has been no great quantity of fire kept, and especially Such as has Served for the cements of the walls of ftablcs, or the like. Mr. Petit qhofe from fuch a wall twelve pounds of old Mor- tar; this he had beat to powder, and poured upon it eighteen pints of water; the whole was then fet over .the fire, and Stirred from time to time for three or four hours, that the water might be well tinctured from the Mortar ; after this the water was filtred through paper, and was then found to be tinctured to a pale yellow, tranfparent, bitter, and fome- what acrid to the tafte.

The impregnation may be made without heat, by only ftir- ring the Mortar about for nine or ten days in cold water, and the quantity of the Salts taken up will be according to the goodnefs of the Mortar and the quantity of water employed. The common Specific gravity of this liquor to water, is as 32 to 31, or thereabouts. Mr. Petit having procured the tincture of fifty pounds of Mortar by Several impregnations in Seventy- two French pints of water, evaporated it fa far till it appeared highly charged with .Saline particles, tafting very acrid and bitter, and being of a brownifh red colour ; and its fpecific gravity was in this State to water, as 4 to 3, there beino- more in quantity than about four pints. This was ftifi limpid and of a dufky colour, and was afterwards evapo- rated over a gentle fire to the confidence of an extract, which as it cooled became much thicker and firmer, re- fembling butter. This being left open to theair Soon relented into a liquor of the confiftence of a Syrup : Its Specific gra- vity was now to water as 5 to 3 ; but in leaving it open to the air, it continually attracted frefh humidity, and became lefs fpeciBcally heavy. Experiments made with this extract Succeeded in the following manner.

1. It turned the common blue paper to a fine deep red. The impregnations in water uninfpifTated do this alfo in different degrees according to their ftrength.

2. Mixed in equal quantities with fpirit of nitre and with fpirit of Sea-Salt, it made no effervefcence or alteration in either.

3. A leaf gold being put into the mixture of this impregna- tion with fpirit of nitre was immediately diffolved, and in an hour or two afterwards the liquor was much clearer than before.

A leaf of gold being put into the mixture of this impregna- tion and fpirit of Sea-falt, was in the 'fame manner diffolved in a few minutes. It is generally fuppofed indeed that fpirit of fait alone will diflblve gold, but there Seems an error in this founded on the inaccuracy of the preparation of fuch fpirit of Salt ; for MefC Geoffroy and Boutduc have at different times produced before the French Academy fpirit of fait carefully prepared by themfelves, which would not at all diffolve gold, not even with the afiiftance of heat ; even Such Spiritof fait would however be made to diffolve gold by mixing this impregnation with it : So that it has the power of diffolving gold in a great degree.

4. A leaf of Silver being diffolved in Spirit of nitre, and this impregnation of Mortar added to the Solution, the whole be- came turbid, and a precipitation happened, part of the mat- ter